@stephenw10 It's about what I expected; the freebsd defaults are trying to do too much in the interrupt context for these low-power devices. If he runs both tests with firewalling disabled, I'd expect a dramatic improvement in the non-deferred case and hopefully much less so in the deferred case (but that's hard to test in a NAT environment). Also, @themaninspain what are your net.isr.maxthreads and net.isr.numthreads set to?